Infiniti M35/M45 Y50. Manual - part 731

FUEL PUMP

EC-1397

[VK45DE]

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EC

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

Diagnostic Procedure

NBS005Q4

1. 

CHECK OVERALL FUNCTION

1.

Turn ignition switch ON.

2.

Pinch fuel feed hose (1) with two fingers.

OK or NG

OK

>> INSPECTION END

NG

>> GO TO 2.

2. 

CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Turn ignition switch ON.

4.

Check voltage between ECM terminal 113 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 3.

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

38

G/B

Fuel pump control module 
(FPCM) check

[When cranking engine]

Approximately 0V

[Engine is running]

●

Warm-up condition

●

Idle speed

4 - 6V

39

B/R

Fuel pump control module
(FPCM)

[When cranking engine]

0 - 0.5V

[Engine is running]

●

Warm-up condition

●

Idle speed

8 - 12V

113

GR

Fuel pump relay

[Ignition switch: ON]

●

For 1 second after turning ignition switch ON

[Engine is running]

0 - 1.5V

[Ignition switch: ON]

●

More than 1 second after turning ignition 
switch ON

BATTERY VOLTAGE
(11 - 14V)

Fuel pressure pulsation should be felt on the fuel feed 
hose for 1 second after ignition switch is turned ON.

PBIB2721E

Voltage: Battery voltage 

PBIB1187E

EC-1398

[VK45DE]

FUEL PUMP

3. 

CHECK FUEL PUMP POWER SUPPLY CIRCUIT-II

Check voltage between IPDM E/R terminal 40 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 16.

4. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E108, M15

●

Harness for open or short between IPDM E/R and ECM

>> Repair open circuit or short to ground or short to power in harness or connectors.

5. 

CHECK CONDENSER POWER SUPPLY CIRCUIT-I

1.

Turn ignition switch OFF.

2.

Reconnect all harness connectors disconnected.

3.

Disconnect condenser harness connector.

4.

Turn ignition switch ON.

5.

Check voltage between condenser terminal 1 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 9.

NG

>> GO TO 6.

6. 

CHECK 15A FUSE

1.

Turn ignition switch OFF.

2.

Disconnect 15A fuse.

3.

Check 15A fuse.

OK or NG

OK

>> GO TO 7.

NG

>> Replace fuse.

Voltage: Battery voltage

PBIB1926E

Voltage:

Battery voltage should exist for 1 second 
after ignition switch is turned ON.

PBIB0624E

FUEL PUMP

EC-1399

[VK45DE]

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EC

7. 

CHECK CONDENSER POWER SUPPLY CIRCUIT-II

1.

Disconnect IPDM E/R harness connector E8.

2.

Check harness continuity between IPDM E/R terminal 39 and condenser terminal 1.
Refer to Wiring Diagram.

3.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 16.

NG

>> GO TO 8.

8. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E106, B4

●

Harness connectors B65, B434

●

IPDM E/R connector E8

●

Harness for open or short between IPDM E/R and condenser

>> Repair open circuit or short to ground or short to power in harness or connectors.

9. 

CHECK CONDENSER GROUND CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect dropping resistor harness connector.

3.

Check harness continuity between condenser terminal 2 and dropping resistor terminal 2.
Refer to Wiring Diagram. 

4.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 10.

10. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors B65, B434

●

Harness for open or short between condenser and dropping resistor

>> Repair open circuit or short to ground or short to power in harness or connectors.

Continuity should exist.

: Vehicle front

1.

FPCM

2.

Dropping resistor

Continuity should exist.

PBIB2708E

EC-1400

[VK45DE]

FUEL PUMP

11. 

CHECK CONDENSER

Refer to 

EC-1401, "Component Inspection"

 .

OK or NG

OK

>> GO TO 12.

NG

>> Replace condenser.

12. 

CHECK FUEL PUMP POWER SUPPLY CIRCUIT-III

1.

Turn ignition switch OFF.

2.

Disconnect harness connectors B65, B434.

3.

Disconnect “fuel level sensor unit and fuel pump” harness con-
nector (1).

–

Illustration shows the view with rear seat cushion and inspection
hole cover (RH) removed.

–

: Vehicle front

4.

Check harness continuity between the following;
harness connector B434 terminal 7 and “fuel level sensor unit and fuel pump” terminal 1, 
“fuel level sensor unit and fuel pump” terminal 3 and harness connector B434 terminal 16, 
harness connector B434 terminal 16 and dropping resistor terminal 2, 
dropping resistor terminal 1 and ground.
Refer to Wiring Diagram.

OK or NG

OK

>> GO TO 14.

NG

>> GO TO 13.

13. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connector B65, B434

●

Harness for open or short between “fuel level sensor unit and fuel pump” and harness connector B434

●

Harness for open or short between “fuel level sensor unit and fuel pump” and dropping resistor

●

Harness for open or short between dropping resistor and ground

>> Repair open circuit or short to ground or short to power in harness or connectors.

14. 

CHECK DROPPING RESISTOR

Refer to 

EC-1401, "Component Inspection"

 .

OK or NG

OK

>> GO TO 15.

NG

>> Replace dropping resistor.

PBIB2706E

Continuity should exist.